The attitude of various types of vehicles, including both waterborne and airborne vehicles, can be controlled using various control surfaces and/or exhaust nozzles or jet vanes. For example, in many vehicles control along the roll axis may be implemented using one or more control surfaces, and control along the pitch and yaw axes of the vehicle may be implemented using the exhaust nozzles. In other vehicles, control along the roll, pitch, and yaw axes may be implemented using exhaust nozzles. In either case, a thrust vector control system may be included to implement control of the exhaust nozzles.
In general, when thrust vector control is implemented in a vehicle, the direction of thrust of one or more vehicle engines is controlled to effect an attitude change. More specifically, the orientation of one or more engine exhaust nozzles is preferably controlled to control the direction of thrust from each engine. To implement this control, the engine exhaust nozzles may be configured to be moveable in at least two degrees of freedom, one associated with the vehicle pitch axis and the other associated with the vehicle yaw axis. One or more actuators may be provided to move each nozzle to a commanded position, to thereby supply appropriate pitch, yaw, and/or roll attitude control.
The vehicle may additionally include a thrust vector actuator control circuit to control movement of the nozzle actuators, and thus the engine nozzles. The control circuit may receive vehicle attitude commands from an onboard flight computer or a remote station, and in turn supplies appropriate nozzle actuation control signals to the nozzle actuators, to thereby effectuate the commanded vehicle attitude. Presently, most of the thrust vector actuator control circuits installed in vehicles are implemented as an analog circuit.
Although the thrust vector actuation control circuits presently used are generally safe, reliable, and robustly designed, the circuits do suffer certain drawbacks. For example, the control circuits may not be configured to allow self-testing of the actuation system and/or individual system components, the control circuits may not allow real-time, continuous communication of actuation system status, and the control circuits may not allow system gains and compensation parameters to be changed during vehicle operation remote from the launch site. Moreover, because the control circuits may be implemented using analog technology, numerous components may be used, which can impact system reliability, weight, and overall cost.
Hence, there is a need for a thrust vector actuation system control circuit that addresses one or more of the above-noted drawbacks. Namely, a control circuit that allows self-testing of the thrust vector actuation system and/or its individual system components, and/or a control circuit that provides real-time, continuous monitoring of at least actuation system status, and/or a control circuit that allows system gain and compensation parameters to be changed during vehicle operation remote from its launch site, and/or a control circuit with increased reliability, reduced weight, and/or reduced cost, relative to present control circuits. The present invention addresses one or more of these drawbacks.